The present invention relates to a device for indicating to the operator of a vehicle the presence of and the distance to an object toward which it may be moving. More specifically, this invention relates to an ultrasonic distance calculator and warning device particularly suitable for pleasure and commercial vehicles for detecting and providing information as to the proximity and location of both stationary and moving objects with respect to various portions of the vehicle.
Generally large vehicles such as trucks, cement mixers, mining equipment and large recreational vehicles such as mobile homes and campers have certain large "blind" spots surrounding the vehicle which cannot be easily observed by the vehicle operator. These blind spots are usually located at the rear of the vehicle where the operator finds the configuration or design of the vehicle obstructs his full view. This is particularly apparent when the vehicle is being moved in reverse, in which case lack of full view may cause collisions resulting in loss of life and property. In order to help avoid such collisions, there is a need for a reliable and inexpensive device for sensing such obstructions and bringing their location and distance from the vehicle to the attention of the vehicle operator.
Other situations in which there is a need for a sensing device to prevent an operator of a vehicle from inadvertently colliding with objects or persons include the movement of mining equipment into areas where vision is obstructed by, for example, mine dust, avoiding collisions between airplane wingtips with other objects when an airplane is taxiing in a confined area, and the movement of tall vehicles beneath low overhanging structures.
In the prior patented art, there has been provided ultrasonic devices which, when attached to the rear of vehicles such as trucks, measure the distance between the tailgate of the vehicle and a loading platform or other object. Such devices utilize ultrasonic pulsing systems which indicate a distance to the nearest object and warn with the use of a buzzer or similar device that the vehicle is too close to the object. In U.S. Pat. No. 3,226,673 a device for ultrasonically indicating objects rearwardly of a vehicle is disclosed in which an echo received by any of several sensors located horizontally on the back of a vehicle causes a rotating light bulb to flash, thereby indicating the presence and distance to the detected object. The device does not, however, indicate the location of the object transversely of the back of the truck.
U.S. Pat. No. 4,015,232 shows several sensors along the front, back and sides of a vehicle which separately detect the presence of an object to indicate which detector the object is closest to. The device does not, however, indicate the distance to the detected object.
The other prior art devices utilize complex and involved circuitry and components to provide information as to the location or distance of objects. Furthermore, the prior art has not provided a unified simple and economical system for simultaneously providing information both as to the distance and location of objects from a sensing system.